Driving mechanism for machines



y 1955 ,N. GRON 3,196,700

DRIVING MECHANISM FOR MACHINES Filed April 30, 1963 2 Sheets-Sheet l[lull-EH. A

INVENTOR. N/cHOLQ; Geo/v BY PENDLE TON, NSC/MON .SE/BOLD W/LL/QMS Qf/ys.

July 27, 1965 N. GRON 3,196,700

DRIVING MECHANISM FOR MACHINES Filed April 30, 1963 V 2 Sheets-Sheet 2INVENTOR.

N/cHoLQ; e/aoN BY PENDLETON, NEUMRN,

sci/501.0 2 WILL/(QM;

United States Patent 3,196,700 DRIVING MECHANISM FOR MACHINES NicholasGron, 10829 S. Wabash Ave., Chicago, Ill. Filed Apr. 30, 1963, Ser. No.276,757 4 Claims. (Cl. '74--110) The present invention relates topower-applying mechanism and has special reference to power mechanismfor operating machines, such, for example, as shears, presses, bendingmachines, press brakes, and others.

More particularly, this invention relates to a mechanical leveragemechanism actuated by a single power member for driving the ram or otherreciprocating part of a machine.

While the present driving mechanism may be employed with many types ofmachines, it is herein disclosed and described in connection with apress brake. There is a single power-applying or driving member which,as illustrated, may comprise a hydraulic cylinder mounted on the centralupper portion of the frame of the press brake. The hydraulic cylinder isarranged so that the piston thereof extends downwardly and isoperatively connected to the inner ends of a pair of longitudinallyextensible and contractible levers positioned adjacent the veriticallyreciprocating ram of the brake. The outer end portions of the levers arepivotally connected to opposite side frames of the press brake. Bearingmembers mounted on the levers and movable longitudinally thereof arepivotally connected to the adjacent ram. As the pivotal connectionsbetween the levers and the ram, in the embodiment illustrated, areintermediate the inner ends of the levers where power is applied and theouter pivot points or fulcrums of the levers, extension of the pistonfrom the hydraulic cylinder will cause the levers to pivot about theirouter pivot points and thereby force the ram downwardly to perform itsintended work. The pivot members connecting the levers to the ram movevertically in straight lines.

Through the use of an adjustable connecting member secured to the outerend of the piston rod, the inner pivot points of the levers may bevaried, thus varying the force exerted on the ram and the length oftravel of the ram.

An object of the present invention is to provide a simple, eflicientpower-applying or driving mechanism for machines of the type having areciprocating ram. Through the use of a single hydraulic cylinder orother power member instead of a plurality thereof, the operatingcontrols may be greatly simplified.

Another object of the present invention is to provide a construction ofthe above type which results in great accuracy of the power stroke andpermits quick and easy variation of the length of the stroke and theamount of power applied.

It is a further object of this invention to provide powerapplying ordriving mechanism which can be used with standard machines with littleor no modification.

Further objects and advantages will be apparent from the followingdescription and claims when considered with the accompanying drawings,in which:

FIGURE 1 is a front elevational view of a press brake havingpower-applying or driving mechanism embodying the present invention;

FIG. 2 is a cross-sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a side elevational view of the apparatus illustrated in FIG.1;

FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 1;

FIG. 5 is a side elevational view of a hydraulic cylinder and connectingmember attached to the piston thereof which may be employed in thepresent construction;

3,196,700 Patented July 27, 1965 FIG. 6 is a front elevational view ofthe hydraulic cylinder and connecting member shown in FIG. 5; and

FIG. 7 is a front elevational view of the levers forming part of thepresent invention and means for connecting them to other parts of theapparatus.

Referring more particularly to the drawings, there is shown a pressbrake having a drive embodying the present invention. The brake issupported on a frame comprising side members 11 and 12 having cutoutportions along their forward edges for the accommodation of parts of themechanism, a top member 13 and a front vertical, transverse portion 14.

A ram 15 is mounted on the frame so as to be capable of verticalreciprocating movement thereon. For this purpose top gibs 16 are securedto the rear face of the ram adjacent opposite side edges by suitablemeans, such as bolts 17, and are shaped to fit over vertical guides 18secured to the frame. Bottom gibs 19 are also secured to the lower rearface of the ram adjacent the lower side edges thereof and fit aboutsimilar vertical guides. Bolts 17 may also be employed for attaching thelower gibs 19 to the rear of the ram 15. This construction permits theram to reciprocate vertically on the frame, but prevents transversemovement of the ram with respect to the frame. The ram is preferablyprovided at its lower edge with a suitable male die 21.

A bed or plate 22 is mounted on the frame adjacent the lower end of themachine. Secured on the bed is a female die 23 arranged to cooperatewith the male die 21 upon'actuation of the driving mechanism of thepress brake. 'An adjusting screw 20 may be provided for verticaladjustment of the bed 22. Suitable means for holding the bed on theframe are also employed. The drive mechanism for actuating the ramincludes a single power member, such as a hydraulic cylinder 23, securedto the top frame portion 13. A piston 24 projects from the lower end ofthe hydraulic cylinder 23 and has mounted on its lower end a bifurcatedconnecting member 25 with a slot 26 extending the full width thereof.The slot separates the front portion 27 from the rear portion 28, andaligned holes extend entirely through the front and rear portions. Asshown particularly in FIG. 6, there are upper central openings 29a withpairs of aligned openings 29b and 29c below and to each side thereof.This permits adjustment of the drive mechanism, as will be explainedhereinafter. The central opening 29a together with each pair of openings29b or 290 preferably define isosceles triangles as illustrated.

A pair of similar levers 31 and 32 extend between the connecting member25 and the opposite side frames of the apparatus. Each lever islongitudinally extensible and contractible. Each has a lever arm housing33 provided with a longitudinal groove 34 which, in the particularembodiment illustrated, extends inwardly from the inner ends of thelever arm housings a major portion of the length thereof. The outer endsof the lever arm housings are pivotally secured to the frame of theapparatus about horizontal pivot members or fulcrums 35. For thispurpose, end frame blocks 36 are secured to opposite sides of theapparatus by suitable means, such as bolts 37. The pivot members, suchas the pins 35, extend through the end frame blocks and are secured tothe lever arm housings 33, as shown particularly in FIG. 4. This permitsthe lever arm housings to pivot vertically about the horizontal pivotpins 35.

Each lever 31 and 32 also includesa lever arm 38, the inner end of whichis of a size and shape to slidably fit in the groove 34 of itscooperating lever arm housing 33. The front of the groove is closed bythe ram 15 as shown in FIGS. 3 and 4. One of the lever arms 38, such asthat of the lever 31, has its inner end rear- 3 wardly oifset asufficient distance to permit it to overlie the inner end of the otherlever arm 38 forming part of the lever 32 as appears particularly inFIG. 2. The inner ends of the lever arms 38 are provided with openings39a, 39b and 390 spaced and arranged to coincide with the openings inthe connecting member 25.

Slidably positioned in the grooves 3 between the inner ends of the leverarms and the ends of the grooves are bearing members 41 which areconnected to the ram by means of pins 42. The pins 42 extend throughopenings in the ram 15, preferably being fixedly held therein, and intothe bearing members 41. With this construction, the ram moves verticallyas the levers 31 and 32 are pivoted about their pivots or fulcrums 35.

In the embodiment illustrated, the end openings of the lever arms 38 arepivotally connected to the center opening 29a of the connecting member25. This may be accomplished by a pin 43 which projects through the rearportion 28 of the connecting member 25, the inner ends of the lever arms33 and the aligned openings in the forward portion 27 of the connectingmember. press brake, illustrated in the drawings, is in open positionwith the inner ends of the lever arms above the pivots or fulcrums 35 ofthe lever arm housings. Suitable controls (not shown) are provided forcontrolling the operation of the hydraulic cylinder. By a selection ofthe proper controls, the drive may be actuated for inching, singlestroking, or continuous operation of the ram. When fluid is supplied to.the hydraulic cylinder abovethe piston, the piston rod is forceddownwardly, forcing the inner ends of the levers 31 and 32 downwardlyabout their pivots 35' During the downward stroke, the levers decreasein length due to their telescopic action until the two levers arelongitudinally aligned. Simultaneously, the bearings 41 move toward theends of the slots 34 and the pins 42 move'vertically downwardly. If thestroke of the piston is sufficient to bring the connection between theinner ends of the levers and the connecting member below the pivots35,the levers gradually increase in length again.

The length of the stroke of the ram and the power applied by the maledie carried by the ram may be readily varied by changing the points atwhich the inner ends of the lever arms are connected to the connectingmember 25. With the end openings 39111 of the lever arms 38 positionedover the hole 2% in the connecting member, as illustrated, maximum poweris applied to theram, although the distance of movement of the ram isleast. That is because the ratio of the distances from the pin 42 to thepivot points of the inner ends of the lever arms and from the pin 42 tothe fulcrum is greatest. If the inner ends of the levers are pivotallyconnected to the connecting member 25 through the holes 29c of theconnecting member and 390 of the lever arms, the ram will be moved amaximumdistance but minimum force will be applied. By providing variousholes in the connecting member and in the lever arms, the distance ofmovement of the ram and the force applied to. the work may be readilycontrolled. 7

With the connecting member positioned midway between the sides of theram; and the hydraulic cylinder applying the same force to' the ramthrough each pin 4-2, both sides of the ram and die thereon are forceddown equally. v

The present invention has been described in connection with the use of ahydraulic cylinder 23. In place of a hydraulic cylinder, any othersuitable power means may be used for effecting pivotal movement of thelevers 31 and 32 about their respective fulcrums- The embodiment of theinvention disclosed involves a construction in which the pivot orfulcrum of each lever is adjacent the outer end of the lever, and theconnection between the lever and the ram is intermediate the fulcrum andpoint that power is applied to the lever. Other types of levers may beemployed. For example, it would be The 7 possible to have the fulcrum orpivot 35 inwardly of the connection between the bearings 41 and the ram.In such case, the power stroke would be reversed, and the ram would beforced downwardly when the piston rod is moved upwardly toward the upperend of the cylinder. The mechanism sides as used herein has reference tothe central longitudinal axis of movement of said ram whether verticalor otherwise.

While particular embodiments of this invention have been illustrated anddescribed, it will be understood, of course, that the invention is notto be limited thereto since many modifications may be made, and it iscontemplated, therefore, by the appended claims, to cover anymodifications that come within the true scope of this invention.

I claim:

I. The combination with mechanism having a frame and a ram mounted onsaid frame for reciprocating movement, of means for driving said ramcomprising a power member, a pair of similar longitudinally extensibleand contractible levers adjacent one face of said ram, said levershavingtheir inner end portions operatively connected to said powermember and diverging outwardly therefrom to pivots on said frameportions at opposite sides of said mechanism equidistant from theconnections of said levers to said power member, each of said leverscomprising an outer housing portion having a longitudinal slot thereincommunicating with the side thereof adjacent said ram pivotallyconnected to one of said pivots and an inner member having its outer endslidably fitting in said slot for longitudinal movement therein with itsinner end portion operatively connected to said power member for pivotalmovement with respect thereto, a bearing member mounted in each of saidslots for longitudinal movement therein beteen the outer end of saidinner member and the end of the slot in the outer member, and means forpivotally connecting said bearing members and the ram portions adjacentthereto, whereby actuation of said power member causes said levers topivot about their pivots on said frame and effect reciprocal movement ofsaid ram in said frame. 7 I

2. The combination with mechanism having a frame and a ram mounted onsaid frame for vertical reciprocating movement, of means for drivingsaid ram comprising a power unit mounted on said frame having areciprocating connecting portion movable in the direction of movement ofsaid ram, a pair of similar longitudinally extensible and contractiblelevers adjacent one face of said ram extending between said drivingportion andsimilarly positioned pivots on opposite sides of said frameequidistant 1 from the connections of said levers to said drivingportion,

each of said levers comprising a lever arm and a lever arm housing, saidhousing being pivotally mounted adjacent its outer end on one of saidpivots and having a longitudinal groove extending from its inner endtoward the pivot a substantial portion of the length thereof, a bearingmember movably positioned in said groove a substantial distance from theopen end thereof and being secured to an adjacent portion of said ram bya connecting member, said groove communicating with the side of saidlever arm housing adjacent the ram to permit said bearing and connectingmembers to move longitudinally of said housing and. vertically withrespect to said frame upon pivotal movement of said lever arm housing, alever arm secured to said connecting portion and having its outer endslidably fitted into said groove, the length of said lever arm beingsuch that when the inner end of said lever arm is at a maximum distancefrom said pivot the outer end of said lever arm will extend a distanceinto said groove and when the inner end of said lever is closest to saidpivot the outer end of said lever arm will lie inwardly of said bearingmember, whereby actuation of the power applying member causes saidlevers to pivot about their pivot points and effect reciprocatingmovement of said ram with respect to said frame.

3. The combination with mechanism having a frame and a ram mounted onsaid frame for vertical reciprocating movement, of means for drivingsaid ram comprising a power unit mounted on said frame having areciprocating connecting portion movable centrally of the ram in thedirection of movement thereof, a pair of similar longitudinallyextensible and contractible levers adjacent one face of said ramextending between said connecting portion and similarly positionedpivots on opposite sides of said frame, each of said levers comprising alever arm and a lever arm housing, said housing being pivotallyconnected adjacent its outer end to one of said pivots and having alongitudinal groove extending from its inner end toward the pivot asubstantial portion of the length thereof, a bearing member movablypositioned in said groove a substantial distance from the open endthereof and being secured to an adjacent fixed portion of said ram by aconnecting member, said groove communicating with the side of said leverarm housing adjacent the ram to permit said bearing and connectingmembers to move longitudinally of said housing and vertically Withrespect to said frame upon pivotal movement of said lever arm housing, alever arm secured to said connecting portion and having its outer endslidably fitted into said groove, the length of said lever arm beingsuch that when the inner end of said lever arm is at a maximum distancefrom said pivot the outer end of said lever arm will extend a distanceinto said groove and when the inner end of said lever is closest to saidpivot the outer end of said lever arm will be inwardly of said bearingmember, whereby actuation of the power unit causes said levers to pivotabout their pivot points and effect reciprocating movement of said ramwith respect to said frame.

4. The combination with mechanism having a frame and a ram mounted onsaid frame for vertical reciprocating movement, of means for drivingsaid ram comprising a single reciprocating power member mounted on theupper portion of said frame substantially midway between opposite sidesthereof, a connecting element on said power member for movementtherewith in the direction of movement of said ram, a pair of similarlongitudinally extensible and contractible levers adjacent one face ofsaid ram diverging downwardly and outwardly a similar distance atsubstantially equal angles to the path of movement of said ram from saidconnecting element to similarly positioned pivots on opposite sides ofsaid frame, each of said levers comprising a lever arm and a lever armhousing, said housing being pivotally mounted adjacent its outer end onone of said pivots and having a longitudinal groove extending from itsinner end toward the pivot a major portion of the length thereof, abearing member movably positioned in said groove a substantial distancefrom the open end thereof and being pivotally secured to an adjacentfixed portion of said ram by a connecting member extending substantiallynormal to the general plane of said ram, said groove communicating withthe side of said lever arm housing adjacent the ram to permit saidbearing and connecting members to move longitudinally of said housingand vertically with respect to said frame upon pivotal movement of saidlever arm housing, a lever arm adjustably secured to said connectingelement and having its outer end slidably fitted into said groove, thelength of said lever arm being such that when the inner end of saidlever arm is at a maximum distance from said pivot the outer end of saidlever arm will extend a distance into said groove and when the inner endof said lever is closest to said pivot the outer end of said lever armwill lie inwardly of said bearing member, whereby actuation of the powerapplying member causes said levers to pivot about their pivot points andeffect reciprocating movement of said ram with respect to said frame.

References Cited by the Examiner UNITED STATES PATENTS 1,762,614 6/30Delfino 74-40 X 2,109,721 3/38 Drevlow et a1 *74--45 2,135,299 11/38Benander --271 X 2,375,398 5/45 Wilkins l00-293 2,884,573 4/59 Watson74-110 X FOREIGN PATENTS 962,440 6/50 France. 406,962 8/44 Italy.

BROUGHTON G. DURHAM, Primary Examiner.

1. THE COMBINATION WITH MECHANISM HAVING A FRAME AND A RAM MOUNTED ONSAID FRAME FOR RECIPROCATING MOVEMENT, OF MEANS FOR DRIVING SAID RAMCOMPRISING A POER MEMBER, A PAIR OF SIMILAR LONGITUDINALLY EXTENSIBLEAND CONTRACTIBLE LEVERS ADJACENT ONE FACE OF SAID RAM, SAID LEVERSHAVING THEIR INNER END PORTIONS OPERATIVELY CONNECTED TO SAID POWERMEMBER AND DIVERGING OUTWARDLY THEREFROM TO PIVOTS ON SAID FRAMEPORTIONS AT OPPOSITE SIDES OF SAID MECHANISMS EQUIDISTANT FROM THECONNECTIONS OF SAID LEVERS TO SAID POWER MEMBER, EACH OF AID LEVERSCOMPRISING AN OUTER HOUSING PORTION HAVING A LONGITUDINAL SLOT THEREINCOMMUNICATION WITH THE SIDE THEREOF ADJACENT SAID RAM PIVOTALLYCONNECTED TO ONE OF SAID PIVOTS AND AN INNER MEMBER HAVING ITS OUTER ENDSLIDABLY FITTING IN SAID SLOT FOR LONGITUDINAL MOVEMENT THEREIN WITH ITSINNER END PORTION OPERAWTIVELY CONNECTED TO SAID POWER MEMBER FORPIVOTAL MOVEMENT WITH RESPECT THERETO, A BEARING MEMBER MOUNTED IN EACHOF SAID SLOTS FOR LONGITUDINAL MOVEMENT THEREIN BETWEEN THE OUTER END OFSAID INNER MEMBER AND THE END OF THE SLOT IN THE OUTER MEMBER, AND MEANSFOR PIVOTALLY CONNECTING SAID BEARING MEMBERS AND THE RAM PORTIONSADJACENT THERETO, WHEREBY ACTUATION OF SAID POWER MEMBER CAUSES SAIDLEVERS TO PIVOT ABOUT THEIR PIVOTS ON SAID FRAME AND EFFECT RECIPROCALMOVEMENT OF SAID RAM IN SAID FRAME.